I boil them. Nothing special. Since changing my diet (and my methods - going for simplicity), many of these foods are still new to me.

I rinse the dried beans in water, remove stones, put them in a pot with lots of water, simmer, half-covered, for, oh, 4 or 5 hours, "until they're done." I add water to always keep the beans immersed, until the end when (as you can see) I boil away most of it.

I've found the longer you cook these beans, the easier they are to digest. Sprouting improves digestion too, but I usually don't take the time (or plan ahead that much). I've been told a pressure cooker works well, cuts the time.

The black beans are starchier than the adzuki beans. The black get very soft and color/thicken the sauce. The adzuki hold their shape or texture a tiny bit more. I'm not concerned about seeing an intact bean shape, I like these this way.

When done, you really have to season them. At least salt. Peppers/chilies go well. Sautéed onions/garlic. Here's where all the great cooks take off - yourself included!

thanks very much for the instructionsi did manage to find some black beans like the ones in your photo, and i am going to try out some kind of dip like yours. these beans are very different to the way greeks eat beans

Re the sweetness of adzuki beans, in Japan they're used to make a type of candy! I made it once long ago, and it was kind of good. There is an essential sweetness there that helps it along. Here's a link to some adzuki recipe desserts: